dvb_net.c

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/*
 * dvb_net.c
 *
 * Copyright (C) 2001 Convergence integrated media GmbH
 *                    Ralph Metzler <[email protected]>
 * Copyright (C) 2002 Ralph Metzler <[email protected]>
 *
 * ULE Decapsulation code:
 * Copyright (C) 2003, 2004 gcs - Global Communication & Services GmbH.
 *                      and Department of Scientific Computing
 *                          Paris Lodron University of Salzburg.
 *                          Hilmar Linder <[email protected]>
 *                      and Wolfram Stering <[email protected]>
 *
 * ULE Decaps according to RFC 4326.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 * Or, point your browser to http://www.gnu.org/copyleft/gpl.html
 */

/*
 * ULE ChangeLog:
 * Feb 2004: hl/ws v1: Implementing draft-fair-ipdvb-ule-01.txt
 *
 * Dec 2004: hl/ws v2: Implementing draft-ietf-ipdvb-ule-03.txt:
 *                       ULE Extension header handling.
 *                     Bugreports by Moritz Vieth and Hanno Tersteegen,
 *                       Fraunhofer Institute for Open Communication Systems
 *                       Competence Center for Advanced Satellite Communications.
 *                     Bugfixes and robustness improvements.
 *                     Filtering on dest MAC addresses, if present (D-Bit = 0)
 *                     ULE_DEBUG compile-time option.
 * Apr 2006: cp v3:    Bugfixes and compliency with RFC 4326 (ULE) by
 *                       Christian Praehauser <[email protected]>,
 *                       Paris Lodron University of Salzburg.
 */

/*
 * FIXME / TODO (dvb_net.c):
 *
 * Unloading does not work for 2.6.9 kernels: a refcount doesn't go to zero.
 *
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/dvb/net.h>
#include <linux/uio.h>
#include <asm/uaccess.h>
#include <linux/crc32.h>
#include <linux/mutex.h>
#include <linux/sched.h>

#include "dvb_demux.h"
#include "dvb_net.h"

static int dvb_net_debug;
module_param(dvb_net_debug, int, 0444);
MODULE_PARM_DESC(dvb_net_debug, "enable debug messages");

#define dprintk(x...) do { if (dvb_net_debug) printk(x); } while (0)


static inline __u32 iov_crc32( __u32 c, struct kvec *iov, unsigned int cnt )
{
    unsigned int j;
    for (j = 0; j < cnt; j++)
        c = crc32_be( c, iov[j].iov_base, iov[j].iov_len );
    return c;
}


#define DVB_NET_MULTICAST_MAX 10

#undef ULE_DEBUG

#ifdef ULE_DEBUG

#define MAC_ADDR_PRINTFMT "%.2x:%.2x:%.2x:%.2x:%.2x:%.2x"
#define MAX_ADDR_PRINTFMT_ARGS(macap) (macap)[0],(macap)[1],(macap)[2],(macap)[3],(macap)[4],(macap)[5]

#define isprint(c)  ((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || (c >= '0' && c <= '9'))

static void hexdump( const unsigned char *buf, unsigned short len )
{
    char str[80], octet[10];
    int ofs, i, l;

    for (ofs = 0; ofs < len; ofs += 16) {
        sprintf( str, "%03d: ", ofs );

        for (i = 0; i < 16; i++) {
            if ((i + ofs) < len)
                sprintf( octet, "%02x ", buf[ofs + i] );
            else
                strcpy( octet, "   " );

            strcat( str, octet );
        }
        strcat( str, "  " );
        l = strlen( str );

        for (i = 0; (i < 16) && ((i + ofs) < len); i++)
            str[l++] = isprint( buf[ofs + i] ) ? buf[ofs + i] : '.';

        str[l] = '\0';
        printk( KERN_WARNING "%s\n", str );
    }
}

#endif

struct dvb_net_priv {
    int in_use;
    u16 pid;
    struct net_device *net;
    struct dvb_net *host;
    struct dmx_demux *demux;
    struct dmx_section_feed *secfeed;
    struct dmx_section_filter *secfilter;
    struct dmx_ts_feed *tsfeed;
    int multi_num;
    struct dmx_section_filter *multi_secfilter[DVB_NET_MULTICAST_MAX];
    unsigned char multi_macs[DVB_NET_MULTICAST_MAX][6];
    int rx_mode;
#define RX_MODE_UNI 0
#define RX_MODE_MULTI 1
#define RX_MODE_ALL_MULTI 2
#define RX_MODE_PROMISC 3
    struct work_struct set_multicast_list_wq;
    struct work_struct restart_net_feed_wq;
    unsigned char feedtype;         /* Either FEED_TYPE_ or FEED_TYPE_ULE */
    int need_pusi;              /* Set to 1, if synchronization on PUSI required. */
    unsigned char tscc;         /* TS continuity counter after sync on PUSI. */
    struct sk_buff *ule_skb;        /* ULE SNDU decodes into this buffer. */
    unsigned char *ule_next_hdr;        /* Pointer into skb to next ULE extension header. */
    unsigned short ule_sndu_len;        /* ULE SNDU length in bytes, w/o D-Bit. */
    unsigned short ule_sndu_type;       /* ULE SNDU type field, complete. */
    unsigned char ule_sndu_type_1;      /* ULE SNDU type field, if split across 2 TS cells. */
    unsigned char ule_dbit;         /* Whether the DestMAC address present
                         * or not (bit is set). */
    unsigned char ule_bridged;      /* Whether the ULE_BRIDGED extension header was found. */
    int ule_sndu_remain;            /* Nr. of bytes still required for current ULE SNDU. */
    unsigned long ts_count;         /* Current ts cell counter. */
    struct mutex mutex;
};


static __be16 dvb_net_eth_type_trans(struct sk_buff *skb,
                      struct net_device *dev)
{
    struct ethhdr *eth;
    unsigned char *rawp;

    skb_reset_mac_header(skb);
    skb_pull(skb,dev->hard_header_len);
    eth = eth_hdr(skb);

    if (*eth->h_dest & 1) {
        if(memcmp(eth->h_dest,dev->broadcast, ETH_ALEN)==0)
            skb->pkt_type=PACKET_BROADCAST;
        else
            skb->pkt_type=PACKET_MULTICAST;
    }

    if (ntohs(eth->h_proto) >= 1536)
        return eth->h_proto;

    rawp = skb->data;

    if (*(unsigned short *)rawp == 0xFFFF)
        return htons(ETH_P_802_3);

    return htons(ETH_P_802_2);
}

#define TS_SZ   188
#define TS_SYNC 0x47
#define TS_TEI  0x80
#define TS_SC   0xC0
#define TS_PUSI 0x40
#define TS_AF_A 0x20
#define TS_AF_D 0x10

/* ULE Extension Header handlers. */

#define ULE_TEST    0
#define ULE_BRIDGED 1

#define ULE_OPTEXTHDR_PADDING 0

static int ule_test_sndu( struct dvb_net_priv *p )
{
    return -1;
}

static int ule_bridged_sndu( struct dvb_net_priv *p )
{
    struct ethhdr *hdr = (struct ethhdr*) p->ule_next_hdr;
    if(ntohs(hdr->h_proto) < 1536) {
        int framelen = p->ule_sndu_len - ((p->ule_next_hdr+sizeof(struct ethhdr)) - p->ule_skb->data);
        /* A frame Type < 1536 for a bridged frame, introduces a LLC Length field. */
        if(framelen != ntohs(hdr->h_proto)) {
            return -1;
        }
    }
    /* Note:
     * From RFC4326:
     *  "A bridged SNDU is a Mandatory Extension Header of Type 1.
     *   It must be the final (or only) extension header specified in the header chain of a SNDU."
     * The 'ule_bridged' flag will cause the extension header processing loop to terminate.
     */
    p->ule_bridged = 1;
    return 0;
}

static int ule_exthdr_padding(struct dvb_net_priv *p)
{
    return 0;
}

static int handle_one_ule_extension( struct dvb_net_priv *p )
{
    /* Table of mandatory extension header handlers.  The header type is the index. */
    static int (*ule_mandatory_ext_handlers[255])( struct dvb_net_priv *p ) =
        { [0] = ule_test_sndu, [1] = ule_bridged_sndu, [2] = NULL,  };

    /* Table of optional extension header handlers.  The header type is the index. */
    static int (*ule_optional_ext_handlers[255])( struct dvb_net_priv *p ) =
        { [0] = ule_exthdr_padding, [1] = NULL, };

    int ext_len = 0;
    unsigned char hlen = (p->ule_sndu_type & 0x0700) >> 8;
    unsigned char htype = p->ule_sndu_type & 0x00FF;

    /* Discriminate mandatory and optional extension headers. */
    if (hlen == 0) {
        /* Mandatory extension header */
        if (ule_mandatory_ext_handlers[htype]) {
            ext_len = ule_mandatory_ext_handlers[htype]( p );
            if(ext_len >= 0) {
                p->ule_next_hdr += ext_len;
                if (!p->ule_bridged) {
                    p->ule_sndu_type = ntohs(*(__be16 *)p->ule_next_hdr);
                    p->ule_next_hdr += 2;
                } else {
                    p->ule_sndu_type = ntohs(*(__be16 *)(p->ule_next_hdr + ((p->ule_dbit ? 2 : 3) * ETH_ALEN)));
                    /* This assures the extension handling loop will terminate. */
                }
            }
            // else: extension handler failed or SNDU should be discarded
        } else
            ext_len = -1;   /* SNDU has to be discarded. */
    } else {
        /* Optional extension header.  Calculate the length. */
        ext_len = hlen << 1;
        /* Process the optional extension header according to its type. */
        if (ule_optional_ext_handlers[htype])
            (void)ule_optional_ext_handlers[htype]( p );
        p->ule_next_hdr += ext_len;
        p->ule_sndu_type = ntohs( *(__be16 *)(p->ule_next_hdr-2) );
        /*
         * note: the length of the next header type is included in the
         * length of THIS optional extension header
         */
    }

    return ext_len;
}

static int handle_ule_extensions( struct dvb_net_priv *p )
{
    int total_ext_len = 0, l;

    p->ule_next_hdr = p->ule_skb->data;
    do {
        l = handle_one_ule_extension( p );
        if (l < 0)
            return l;   /* Stop extension header processing and discard SNDU. */
        total_ext_len += l;
#ifdef ULE_DEBUG
        dprintk("handle_ule_extensions: ule_next_hdr=%p, ule_sndu_type=%i, "
            "l=%i, total_ext_len=%i\n", p->ule_next_hdr,
            (int) p->ule_sndu_type, l, total_ext_len);
#endif

    } while (p->ule_sndu_type < 1536);

    return total_ext_len;
}


static inline void reset_ule( struct dvb_net_priv *p )
{
    p->ule_skb = NULL;
    p->ule_next_hdr = NULL;
    p->ule_sndu_len = 0;
    p->ule_sndu_type = 0;
    p->ule_sndu_type_1 = 0;
    p->ule_sndu_remain = 0;
    p->ule_dbit = 0xFF;
    p->ule_bridged = 0;
}

static void dvb_net_ule( struct net_device *dev, const u8 *buf, size_t buf_len )
{
    struct dvb_net_priv *priv = netdev_priv(dev);
    unsigned long skipped = 0L;
    const u8 *ts, *ts_end, *from_where = NULL;
    u8 ts_remain = 0, how_much = 0, new_ts = 1;
    struct ethhdr *ethh = NULL;
    bool error = false;

#ifdef ULE_DEBUG
    /* The code inside ULE_DEBUG keeps a history of the last 100 TS cells processed. */
    static unsigned char ule_hist[100*TS_SZ];
    static unsigned char *ule_where = ule_hist, ule_dump;
#endif

    /* For all TS cells in current buffer.
     * Appearently, we are called for every single TS cell.
     */
    for (ts = buf, ts_end = buf + buf_len; ts < ts_end; /* no default incr. */ ) {

        if (new_ts) {
            /* We are about to process a new TS cell. */

#ifdef ULE_DEBUG
            if (ule_where >= &ule_hist[100*TS_SZ]) ule_where = ule_hist;
            memcpy( ule_where, ts, TS_SZ );
            if (ule_dump) {
                hexdump( ule_where, TS_SZ );
                ule_dump = 0;
            }
            ule_where += TS_SZ;
#endif

            /* Check TS error conditions: sync_byte, transport_error_indicator, scrambling_control . */
            if ((ts[0] != TS_SYNC) || (ts[1] & TS_TEI) || ((ts[3] & TS_SC) != 0)) {
                printk(KERN_WARNING "%lu: Invalid TS cell: SYNC %#x, TEI %u, SC %#x.\n",
                       priv->ts_count, ts[0], ts[1] & TS_TEI >> 7, ts[3] & 0xC0 >> 6);

                /* Drop partly decoded SNDU, reset state, resync on PUSI. */
                if (priv->ule_skb) {
                    dev_kfree_skb( priv->ule_skb );
                    /* Prepare for next SNDU. */
                    dev->stats.rx_errors++;
                    dev->stats.rx_frame_errors++;
                }
                reset_ule(priv);
                priv->need_pusi = 1;

                /* Continue with next TS cell. */
                ts += TS_SZ;
                priv->ts_count++;
                continue;
            }

            ts_remain = 184;
            from_where = ts + 4;
        }
        /* Synchronize on PUSI, if required. */
        if (priv->need_pusi) {
            if (ts[1] & TS_PUSI) {
                /* Find beginning of first ULE SNDU in current TS cell. */
                /* Synchronize continuity counter. */
                priv->tscc = ts[3] & 0x0F;
                /* There is a pointer field here. */
                if (ts[4] > ts_remain) {
                    printk(KERN_ERR "%lu: Invalid ULE packet "
                           "(pointer field %d)\n", priv->ts_count, ts[4]);
                    ts += TS_SZ;
                    priv->ts_count++;
                    continue;
                }
                /* Skip to destination of pointer field. */
                from_where = &ts[5] + ts[4];
                ts_remain -= 1 + ts[4];
                skipped = 0;
            } else {
                skipped++;
                ts += TS_SZ;
                priv->ts_count++;
                continue;
            }
        }

        if (new_ts) {
            /* Check continuity counter. */
            if ((ts[3] & 0x0F) == priv->tscc)
                priv->tscc = (priv->tscc + 1) & 0x0F;
            else {
                /* TS discontinuity handling: */
                printk(KERN_WARNING "%lu: TS discontinuity: got %#x, "
                       "expected %#x.\n", priv->ts_count, ts[3] & 0x0F, priv->tscc);
                /* Drop partly decoded SNDU, reset state, resync on PUSI. */
                if (priv->ule_skb) {
                    dev_kfree_skb( priv->ule_skb );
                    /* Prepare for next SNDU. */
                    // reset_ule(priv);  moved to below.
                    dev->stats.rx_errors++;
                    dev->stats.rx_frame_errors++;
                }
                reset_ule(priv);
                /* skip to next PUSI. */
                priv->need_pusi = 1;
                continue;
            }
            /* If we still have an incomplete payload, but PUSI is
             * set; some TS cells are missing.
             * This is only possible here, if we missed exactly 16 TS
             * cells (continuity counter wrap). */
            if (ts[1] & TS_PUSI) {
                if (! priv->need_pusi) {
                    if (!(*from_where < (ts_remain-1)) || *from_where != priv->ule_sndu_remain) {
                        /* Pointer field is invalid.  Drop this TS cell and any started ULE SNDU. */
                        printk(KERN_WARNING "%lu: Invalid pointer "
                               "field: %u.\n", priv->ts_count, *from_where);

                        /* Drop partly decoded SNDU, reset state, resync on PUSI. */
                        if (priv->ule_skb) {
                            error = true;
                            dev_kfree_skb(priv->ule_skb);
                        }

                        if (error || priv->ule_sndu_remain) {
                            dev->stats.rx_errors++;
                            dev->stats.rx_frame_errors++;
                            error = false;
                        }

                        reset_ule(priv);
                        priv->need_pusi = 1;
                        continue;
                    }
                    /* Skip pointer field (we're processing a
                     * packed payload). */
                    from_where += 1;
                    ts_remain -= 1;
                } else
                    priv->need_pusi = 0;

                if (priv->ule_sndu_remain > 183) {
                    /* Current SNDU lacks more data than there could be available in the
                     * current TS cell. */
                    dev->stats.rx_errors++;
                    dev->stats.rx_length_errors++;
                    printk(KERN_WARNING "%lu: Expected %d more SNDU bytes, but "
                           "got PUSI (pf %d, ts_remain %d).  Flushing incomplete payload.\n",
                           priv->ts_count, priv->ule_sndu_remain, ts[4], ts_remain);
                    dev_kfree_skb(priv->ule_skb);
                    /* Prepare for next SNDU. */
                    reset_ule(priv);
                    /* Resync: go to where pointer field points to: start of next ULE SNDU. */
                    from_where += ts[4];
                    ts_remain -= ts[4];
                }
            }
        }

        /* Check if new payload needs to be started. */
        if (priv->ule_skb == NULL) {
            /* Start a new payload with skb.
             * Find ULE header.  It is only guaranteed that the
             * length field (2 bytes) is contained in the current
             * TS.
             * Check ts_remain has to be >= 2 here. */
            if (ts_remain < 2) {
                printk(KERN_WARNING "Invalid payload packing: only %d "
                       "bytes left in TS.  Resyncing.\n", ts_remain);
                priv->ule_sndu_len = 0;
                priv->need_pusi = 1;
                ts += TS_SZ;
                continue;
            }

            if (! priv->ule_sndu_len) {
                /* Got at least two bytes, thus extrace the SNDU length. */
                priv->ule_sndu_len = from_where[0] << 8 | from_where[1];
                if (priv->ule_sndu_len & 0x8000) {
                    /* D-Bit is set: no dest mac present. */
                    priv->ule_sndu_len &= 0x7FFF;
                    priv->ule_dbit = 1;
                } else
                    priv->ule_dbit = 0;

                if (priv->ule_sndu_len < 5) {
                    printk(KERN_WARNING "%lu: Invalid ULE SNDU length %u. "
                           "Resyncing.\n", priv->ts_count, priv->ule_sndu_len);
                    dev->stats.rx_errors++;
                    dev->stats.rx_length_errors++;
                    priv->ule_sndu_len = 0;
                    priv->need_pusi = 1;
                    new_ts = 1;
                    ts += TS_SZ;
                    priv->ts_count++;
                    continue;
                }
                ts_remain -= 2; /* consume the 2 bytes SNDU length. */
                from_where += 2;
            }

            priv->ule_sndu_remain = priv->ule_sndu_len + 2;
            /*
             * State of current TS:
             *   ts_remain (remaining bytes in the current TS cell)
             *   0  ule_type is not available now, we need the next TS cell
             *   1  the first byte of the ule_type is present
             * >=2  full ULE header present, maybe some payload data as well.
             */
            switch (ts_remain) {
                case 1:
                    priv->ule_sndu_remain--;
                    priv->ule_sndu_type = from_where[0] << 8;
                    priv->ule_sndu_type_1 = 1; /* first byte of ule_type is set. */
                    ts_remain -= 1; from_where += 1;
                    /* Continue w/ next TS. */
                case 0:
                    new_ts = 1;
                    ts += TS_SZ;
                    priv->ts_count++;
                    continue;

                default: /* complete ULE header is present in current TS. */
                    /* Extract ULE type field. */
                    if (priv->ule_sndu_type_1) {
                        priv->ule_sndu_type_1 = 0;
                        priv->ule_sndu_type |= from_where[0];
                        from_where += 1; /* points to payload start. */
                        ts_remain -= 1;
                    } else {
                        /* Complete type is present in new TS. */
                        priv->ule_sndu_type = from_where[0] << 8 | from_where[1];
                        from_where += 2; /* points to payload start. */
                        ts_remain -= 2;
                    }
                    break;
            }

            /* Allocate the skb (decoder target buffer) with the correct size, as follows:
             * prepare for the largest case: bridged SNDU with MAC address (dbit = 0). */
            priv->ule_skb = dev_alloc_skb( priv->ule_sndu_len + ETH_HLEN + ETH_ALEN );
            if (priv->ule_skb == NULL) {
                printk(KERN_NOTICE "%s: Memory squeeze, dropping packet.\n",
                       dev->name);
                dev->stats.rx_dropped++;
                return;
            }

            /* This includes the CRC32 _and_ dest mac, if !dbit. */
            priv->ule_sndu_remain = priv->ule_sndu_len;
            priv->ule_skb->dev = dev;
            /* Leave space for Ethernet or bridged SNDU header (eth hdr plus one MAC addr). */
            skb_reserve( priv->ule_skb, ETH_HLEN + ETH_ALEN );
        }

        /* Copy data into our current skb. */
        how_much = min(priv->ule_sndu_remain, (int)ts_remain);
        memcpy(skb_put(priv->ule_skb, how_much), from_where, how_much);
        priv->ule_sndu_remain -= how_much;
        ts_remain -= how_much;
        from_where += how_much;

        /* Check for complete payload. */
        if (priv->ule_sndu_remain <= 0) {
            /* Check CRC32, we've got it in our skb already. */
            __be16 ulen = htons(priv->ule_sndu_len);
            __be16 utype = htons(priv->ule_sndu_type);
            const u8 *tail;
            struct kvec iov[3] = {
                { &ulen, sizeof ulen },
                { &utype, sizeof utype },
                { priv->ule_skb->data, priv->ule_skb->len - 4 }
            };
            u32 ule_crc = ~0L, expected_crc;
            if (priv->ule_dbit) {
                /* Set D-bit for CRC32 verification,
                 * if it was set originally. */
                ulen |= htons(0x8000);
            }

            ule_crc = iov_crc32(ule_crc, iov, 3);
            tail = skb_tail_pointer(priv->ule_skb);
            expected_crc = *(tail - 4) << 24 |
                       *(tail - 3) << 16 |
                       *(tail - 2) << 8 |
                       *(tail - 1);
            if (ule_crc != expected_crc) {
                printk(KERN_WARNING "%lu: CRC32 check FAILED: %08x / %08x, SNDU len %d type %#x, ts_remain %d, next 2: %x.\n",
                       priv->ts_count, ule_crc, expected_crc, priv->ule_sndu_len, priv->ule_sndu_type, ts_remain, ts_remain > 2 ? *(unsigned short *)from_where : 0);

#ifdef ULE_DEBUG
                hexdump( iov[0].iov_base, iov[0].iov_len );
                hexdump( iov[1].iov_base, iov[1].iov_len );
                hexdump( iov[2].iov_base, iov[2].iov_len );

                if (ule_where == ule_hist) {
                    hexdump( &ule_hist[98*TS_SZ], TS_SZ );
                    hexdump( &ule_hist[99*TS_SZ], TS_SZ );
                } else if (ule_where == &ule_hist[TS_SZ]) {
                    hexdump( &ule_hist[99*TS_SZ], TS_SZ );
                    hexdump( ule_hist, TS_SZ );
                } else {
                    hexdump( ule_where - TS_SZ - TS_SZ, TS_SZ );
                    hexdump( ule_where - TS_SZ, TS_SZ );
                }
                ule_dump = 1;
#endif

                dev->stats.rx_errors++;
                dev->stats.rx_crc_errors++;
                dev_kfree_skb(priv->ule_skb);
            } else {
                /* CRC32 verified OK. */
                u8 dest_addr[ETH_ALEN];
                static const u8 bc_addr[ETH_ALEN] =
                    { [ 0 ... ETH_ALEN-1] = 0xff };

                /* CRC32 was OK. Remove it from skb. */
                priv->ule_skb->tail -= 4;
                priv->ule_skb->len -= 4;

                if (!priv->ule_dbit) {
                    /*
                     * The destination MAC address is the
                     * next data in the skb.  It comes
                     * before any extension headers.
                     *
                     * Check if the payload of this SNDU
                     * should be passed up the stack.
                     */
                    register int drop = 0;
                    if (priv->rx_mode != RX_MODE_PROMISC) {
                        if (priv->ule_skb->data[0] & 0x01) {
                            /* multicast or broadcast */
                            if (memcmp(priv->ule_skb->data, bc_addr, ETH_ALEN)) {
                                /* multicast */
                                if (priv->rx_mode == RX_MODE_MULTI) {
                                    int i;
                                    for(i = 0; i < priv->multi_num && memcmp(priv->ule_skb->data, priv->multi_macs[i], ETH_ALEN); i++)
                                        ;
                                    if (i == priv->multi_num)
                                        drop = 1;
                                } else if (priv->rx_mode != RX_MODE_ALL_MULTI)
                                    drop = 1; /* no broadcast; */
                                /* else: all multicast mode: accept all multicast packets */
                            }
                            /* else: broadcast */
                        }
                        else if (memcmp(priv->ule_skb->data, dev->dev_addr, ETH_ALEN))
                            drop = 1;
                        /* else: destination address matches the MAC address of our receiver device */
                    }
                    /* else: promiscuous mode; pass everything up the stack */

                    if (drop) {
#ifdef ULE_DEBUG
                        dprintk("Dropping SNDU: MAC destination address does not match: dest addr: "MAC_ADDR_PRINTFMT", dev addr: "MAC_ADDR_PRINTFMT"\n",
                            MAX_ADDR_PRINTFMT_ARGS(priv->ule_skb->data), MAX_ADDR_PRINTFMT_ARGS(dev->dev_addr));
#endif
                        dev_kfree_skb(priv->ule_skb);
                        goto sndu_done;
                    }
                    else
                    {
                        skb_copy_from_linear_data(priv->ule_skb,
                                  dest_addr,
                                  ETH_ALEN);
                        skb_pull(priv->ule_skb, ETH_ALEN);
                    }
                }

                /* Handle ULE Extension Headers. */
                if (priv->ule_sndu_type < 1536) {
                    /* There is an extension header.  Handle it accordingly. */
                    int l = handle_ule_extensions(priv);
                    if (l < 0) {
                        /* Mandatory extension header unknown or TEST SNDU.  Drop it. */
                        // printk( KERN_WARNING "Dropping SNDU, extension headers.\n" );
                        dev_kfree_skb(priv->ule_skb);
                        goto sndu_done;
                    }
                    skb_pull(priv->ule_skb, l);
                }

                /*
                 * Construct/assure correct ethernet header.
                 * Note: in bridged mode (priv->ule_bridged !=
                 * 0) we already have the (original) ethernet
                 * header at the start of the payload (after
                 * optional dest. address and any extension
                 * headers).
                 */

                if (!priv->ule_bridged) {
                    skb_push(priv->ule_skb, ETH_HLEN);
                    ethh = (struct ethhdr *)priv->ule_skb->data;
                    if (!priv->ule_dbit) {
                         /* dest_addr buffer is only valid if priv->ule_dbit == 0 */
                        memcpy(ethh->h_dest, dest_addr, ETH_ALEN);
                        memset(ethh->h_source, 0, ETH_ALEN);
                    }
                    else /* zeroize source and dest */
                        memset( ethh, 0, ETH_ALEN*2 );

                    ethh->h_proto = htons(priv->ule_sndu_type);
                }
                /* else:  skb is in correct state; nothing to do. */
                priv->ule_bridged = 0;

                /* Stuff into kernel's protocol stack. */
                priv->ule_skb->protocol = dvb_net_eth_type_trans(priv->ule_skb, dev);
                /* If D-bit is set (i.e. destination MAC address not present),
                 * receive the packet anyhow. */
                /* if (priv->ule_dbit && skb->pkt_type == PACKET_OTHERHOST)
                    priv->ule_skb->pkt_type = PACKET_HOST; */
                dev->stats.rx_packets++;
                dev->stats.rx_bytes += priv->ule_skb->len;
                netif_rx(priv->ule_skb);
            }
            sndu_done:
            /* Prepare for next SNDU. */
            reset_ule(priv);
        }

        /* More data in current TS (look at the bytes following the CRC32)? */
        if (ts_remain >= 2 && *((unsigned short *)from_where) != 0xFFFF) {
            /* Next ULE SNDU starts right there. */
            new_ts = 0;
            priv->ule_skb = NULL;
            priv->ule_sndu_type_1 = 0;
            priv->ule_sndu_len = 0;
            // printk(KERN_WARNING "More data in current TS: [%#x %#x %#x %#x]\n",
            //  *(from_where + 0), *(from_where + 1),
            //  *(from_where + 2), *(from_where + 3));
            // printk(KERN_WARNING "ts @ %p, stopped @ %p:\n", ts, from_where + 0);
            // hexdump(ts, 188);
        } else {
            new_ts = 1;
            ts += TS_SZ;
            priv->ts_count++;
            if (priv->ule_skb == NULL) {
                priv->need_pusi = 1;
                priv->ule_sndu_type_1 = 0;
                priv->ule_sndu_len = 0;
            }
        }
    }   /* for all available TS cells */
}

static int dvb_net_ts_callback(const u8 *buffer1, size_t buffer1_len,
                   const u8 *buffer2, size_t buffer2_len,
                   struct dmx_ts_feed *feed, enum dmx_success success)
{
    struct net_device *dev = feed->priv;

    if (buffer2)
        printk(KERN_WARNING "buffer2 not NULL: %p.\n", buffer2);
    if (buffer1_len > 32768)
        printk(KERN_WARNING "length > 32k: %zu.\n", buffer1_len);
    /* printk("TS callback: %u bytes, %u TS cells @ %p.\n",
          buffer1_len, buffer1_len / TS_SZ, buffer1); */
    dvb_net_ule(dev, buffer1, buffer1_len);
    return 0;
}


static void dvb_net_sec(struct net_device *dev,
            const u8 *pkt, int pkt_len)
{
    u8 *eth;
    struct sk_buff *skb;
    struct net_device_stats *stats = &dev->stats;
    int snap = 0;

    /* note: pkt_len includes a 32bit checksum */
    if (pkt_len < 16) {
        printk("%s: IP/MPE packet length = %d too small.\n",
            dev->name, pkt_len);
        stats->rx_errors++;
        stats->rx_length_errors++;
        return;
    }
/* it seems some ISPs manage to screw up here, so we have to
 * relax the error checks... */
#if 0
    if ((pkt[5] & 0xfd) != 0xc1) {
        /* drop scrambled or broken packets */
#else
    if ((pkt[5] & 0x3c) != 0x00) {
        /* drop scrambled */
#endif
        stats->rx_errors++;
        stats->rx_crc_errors++;
        return;
    }
    if (pkt[5] & 0x02) {
        /* handle LLC/SNAP, see rfc-1042 */
        if (pkt_len < 24 || memcmp(&pkt[12], "\xaa\xaa\x03\0\0\0", 6)) {
            stats->rx_dropped++;
            return;
        }
        snap = 8;
    }
    if (pkt[7]) {
        /* FIXME: assemble datagram from multiple sections */
        stats->rx_errors++;
        stats->rx_frame_errors++;
        return;
    }

    /* we have 14 byte ethernet header (ip header follows);
     * 12 byte MPE header; 4 byte checksum; + 2 byte alignment, 8 byte LLC/SNAP
     */
    if (!(skb = dev_alloc_skb(pkt_len - 4 - 12 + 14 + 2 - snap))) {
        //printk(KERN_NOTICE "%s: Memory squeeze, dropping packet.\n", dev->name);
        stats->rx_dropped++;
        return;
    }
    skb_reserve(skb, 2);    /* longword align L3 header */
    skb->dev = dev;

    /* copy L3 payload */
    eth = (u8 *) skb_put(skb, pkt_len - 12 - 4 + 14 - snap);
    memcpy(eth + 14, pkt + 12 + snap, pkt_len - 12 - 4 - snap);

    /* create ethernet header: */
    eth[0]=pkt[0x0b];
    eth[1]=pkt[0x0a];
    eth[2]=pkt[0x09];
    eth[3]=pkt[0x08];
    eth[4]=pkt[0x04];
    eth[5]=pkt[0x03];

    eth[6]=eth[7]=eth[8]=eth[9]=eth[10]=eth[11]=0;

    if (snap) {
        eth[12] = pkt[18];
        eth[13] = pkt[19];
    } else {
        /* protocol numbers are from rfc-1700 or
         * http://www.iana.org/assignments/ethernet-numbers
         */
        if (pkt[12] >> 4 == 6) { /* version field from IP header */
            eth[12] = 0x86; /* IPv6 */
            eth[13] = 0xdd;
        } else {
            eth[12] = 0x08; /* IPv4 */
            eth[13] = 0x00;
        }
    }

    skb->protocol = dvb_net_eth_type_trans(skb, dev);

    stats->rx_packets++;
    stats->rx_bytes+=skb->len;
    netif_rx(skb);
}

static int dvb_net_sec_callback(const u8 *buffer1, size_t buffer1_len,
         const u8 *buffer2, size_t buffer2_len,
         struct dmx_section_filter *filter,
         enum dmx_success success)
{
    struct net_device *dev = filter->priv;

    dvb_net_sec (dev, buffer1, buffer1_len);
    return 0;
}

static int dvb_net_tx(struct sk_buff *skb, struct net_device *dev)
{
    dev_kfree_skb(skb);
    return NETDEV_TX_OK;
}

static u8 mask_normal[6]={0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
static u8 mask_allmulti[6]={0xff, 0xff, 0xff, 0x00, 0x00, 0x00};
static u8 mac_allmulti[6]={0x01, 0x00, 0x5e, 0x00, 0x00, 0x00};
static u8 mask_promisc[6]={0x00, 0x00, 0x00, 0x00, 0x00, 0x00};

static int dvb_net_filter_sec_set(struct net_device *dev,
           struct dmx_section_filter **secfilter,
           u8 *mac, u8 *mac_mask)
{
    struct dvb_net_priv *priv = netdev_priv(dev);
    int ret;

    *secfilter=NULL;
    ret = priv->secfeed->allocate_filter(priv->secfeed, secfilter);
    if (ret<0) {
        printk("%s: could not get filter\n", dev->name);
        return ret;
    }

    (*secfilter)->priv=(void *) dev;

    memset((*secfilter)->filter_value, 0x00, DMX_MAX_FILTER_SIZE);
    memset((*secfilter)->filter_mask,  0x00, DMX_MAX_FILTER_SIZE);
    memset((*secfilter)->filter_mode,  0xff, DMX_MAX_FILTER_SIZE);

    (*secfilter)->filter_value[0]=0x3e;
    (*secfilter)->filter_value[3]=mac[5];
    (*secfilter)->filter_value[4]=mac[4];
    (*secfilter)->filter_value[8]=mac[3];
    (*secfilter)->filter_value[9]=mac[2];
    (*secfilter)->filter_value[10]=mac[1];
    (*secfilter)->filter_value[11]=mac[0];

    (*secfilter)->filter_mask[0] = 0xff;
    (*secfilter)->filter_mask[3] = mac_mask[5];
    (*secfilter)->filter_mask[4] = mac_mask[4];
    (*secfilter)->filter_mask[8] = mac_mask[3];
    (*secfilter)->filter_mask[9] = mac_mask[2];
    (*secfilter)->filter_mask[10] = mac_mask[1];
    (*secfilter)->filter_mask[11]=mac_mask[0];

    dprintk("%s: filter mac=%pM\n", dev->name, mac);
    dprintk("%s: filter mask=%pM\n", dev->name, mac_mask);

    return 0;
}

static int dvb_net_feed_start(struct net_device *dev)
{
    int ret = 0, i;
    struct dvb_net_priv *priv = netdev_priv(dev);
    struct dmx_demux *demux = priv->demux;
    unsigned char *mac = (unsigned char *) dev->dev_addr;

    dprintk("%s: rx_mode %i\n", __func__, priv->rx_mode);
    mutex_lock(&priv->mutex);
    if (priv->tsfeed || priv->secfeed || priv->secfilter || priv->multi_secfilter[0])
        printk("%s: BUG %d\n", __func__, __LINE__);

    priv->secfeed=NULL;
    priv->secfilter=NULL;
    priv->tsfeed = NULL;

    if (priv->feedtype == DVB_NET_FEEDTYPE_MPE) {
        dprintk("%s: alloc secfeed\n", __func__);
        ret=demux->allocate_section_feed(demux, &priv->secfeed,
                     dvb_net_sec_callback);
        if (ret<0) {
            printk("%s: could not allocate section feed\n", dev->name);
            goto error;
        }

        ret = priv->secfeed->set(priv->secfeed, priv->pid, 32768, 1);

        if (ret<0) {
            printk("%s: could not set section feed\n", dev->name);
            priv->demux->release_section_feed(priv->demux, priv->secfeed);
            priv->secfeed=NULL;
            goto error;
        }

        if (priv->rx_mode != RX_MODE_PROMISC) {
            dprintk("%s: set secfilter\n", __func__);
            dvb_net_filter_sec_set(dev, &priv->secfilter, mac, mask_normal);
        }

        switch (priv->rx_mode) {
        case RX_MODE_MULTI:
            for (i = 0; i < priv->multi_num; i++) {
                dprintk("%s: set multi_secfilter[%d]\n", __func__, i);
                dvb_net_filter_sec_set(dev, &priv->multi_secfilter[i],
                               priv->multi_macs[i], mask_normal);
            }
            break;
        case RX_MODE_ALL_MULTI:
            priv->multi_num=1;
            dprintk("%s: set multi_secfilter[0]\n", __func__);
            dvb_net_filter_sec_set(dev, &priv->multi_secfilter[0],
                           mac_allmulti, mask_allmulti);
            break;
        case RX_MODE_PROMISC:
            priv->multi_num=0;
            dprintk("%s: set secfilter\n", __func__);
            dvb_net_filter_sec_set(dev, &priv->secfilter, mac, mask_promisc);
            break;
        }

        dprintk("%s: start filtering\n", __func__);
        priv->secfeed->start_filtering(priv->secfeed);
    } else if (priv->feedtype == DVB_NET_FEEDTYPE_ULE) {
        struct timespec timeout = { 0, 10000000 }; // 10 msec

        /* we have payloads encapsulated in TS */
        dprintk("%s: alloc tsfeed\n", __func__);
        ret = demux->allocate_ts_feed(demux, &priv->tsfeed, dvb_net_ts_callback);
        if (ret < 0) {
            printk("%s: could not allocate ts feed\n", dev->name);
            goto error;
        }

        /* Set netdevice pointer for ts decaps callback. */
        priv->tsfeed->priv = (void *)dev;
        ret = priv->tsfeed->set(priv->tsfeed,
                    priv->pid, /* pid */
                    TS_PACKET, /* type */
                    DMX_TS_PES_OTHER, /* pes type */
                    32768,     /* circular buffer size */
                    timeout    /* timeout */
                    );

        if (ret < 0) {
            printk("%s: could not set ts feed\n", dev->name);
            priv->demux->release_ts_feed(priv->demux, priv->tsfeed);
            priv->tsfeed = NULL;
            goto error;
        }

        dprintk("%s: start filtering\n", __func__);
        priv->tsfeed->start_filtering(priv->tsfeed);
    } else
        ret = -EINVAL;

error:
    mutex_unlock(&priv->mutex);
    return ret;
}

static int dvb_net_feed_stop(struct net_device *dev)
{
    struct dvb_net_priv *priv = netdev_priv(dev);
    int i, ret = 0;

    dprintk("%s\n", __func__);
    mutex_lock(&priv->mutex);
    if (priv->feedtype == DVB_NET_FEEDTYPE_MPE) {
        if (priv->secfeed) {
            if (priv->secfeed->is_filtering) {
                dprintk("%s: stop secfeed\n", __func__);
                priv->secfeed->stop_filtering(priv->secfeed);
            }

            if (priv->secfilter) {
                dprintk("%s: release secfilter\n", __func__);
                priv->secfeed->release_filter(priv->secfeed,
                                  priv->secfilter);
                priv->secfilter=NULL;
            }

            for (i=0; i<priv->multi_num; i++) {
                if (priv->multi_secfilter[i]) {
                    dprintk("%s: release multi_filter[%d]\n",
                        __func__, i);
                    priv->secfeed->release_filter(priv->secfeed,
                                      priv->multi_secfilter[i]);
                    priv->multi_secfilter[i] = NULL;
                }
            }

            priv->demux->release_section_feed(priv->demux, priv->secfeed);
            priv->secfeed = NULL;
        } else
            printk("%s: no feed to stop\n", dev->name);
    } else if (priv->feedtype == DVB_NET_FEEDTYPE_ULE) {
        if (priv->tsfeed) {
            if (priv->tsfeed->is_filtering) {
                dprintk("%s: stop tsfeed\n", __func__);
                priv->tsfeed->stop_filtering(priv->tsfeed);
            }
            priv->demux->release_ts_feed(priv->demux, priv->tsfeed);
            priv->tsfeed = NULL;
        }
        else
            printk("%s: no ts feed to stop\n", dev->name);
    } else
        ret = -EINVAL;
    mutex_unlock(&priv->mutex);
    return ret;
}


static int dvb_set_mc_filter(struct net_device *dev, unsigned char *addr)
{
    struct dvb_net_priv *priv = netdev_priv(dev);

    if (priv->multi_num == DVB_NET_MULTICAST_MAX)
        return -ENOMEM;

    memcpy(priv->multi_macs[priv->multi_num], addr, ETH_ALEN);

    priv->multi_num++;
    return 0;
}


static void wq_set_multicast_list (struct work_struct *work)
{
    struct dvb_net_priv *priv =
        container_of(work, struct dvb_net_priv, set_multicast_list_wq);
    struct net_device *dev = priv->net;

    dvb_net_feed_stop(dev);
    priv->rx_mode = RX_MODE_UNI;
    netif_addr_lock_bh(dev);

    if (dev->flags & IFF_PROMISC) {
        dprintk("%s: promiscuous mode\n", dev->name);
        priv->rx_mode = RX_MODE_PROMISC;
    } else if ((dev->flags & IFF_ALLMULTI)) {
        dprintk("%s: allmulti mode\n", dev->name);
        priv->rx_mode = RX_MODE_ALL_MULTI;
    } else if (!netdev_mc_empty(dev)) {
        struct netdev_hw_addr *ha;

        dprintk("%s: set_mc_list, %d entries\n",
            dev->name, netdev_mc_count(dev));

        priv->rx_mode = RX_MODE_MULTI;
        priv->multi_num = 0;

        netdev_for_each_mc_addr(ha, dev)
            dvb_set_mc_filter(dev, ha->addr);
    }

    netif_addr_unlock_bh(dev);
    dvb_net_feed_start(dev);
}


static void dvb_net_set_multicast_list (struct net_device *dev)
{
    struct dvb_net_priv *priv = netdev_priv(dev);
    schedule_work(&priv->set_multicast_list_wq);
}


static void wq_restart_net_feed (struct work_struct *work)
{
    struct dvb_net_priv *priv =
        container_of(work, struct dvb_net_priv, restart_net_feed_wq);
    struct net_device *dev = priv->net;

    if (netif_running(dev)) {
        dvb_net_feed_stop(dev);
        dvb_net_feed_start(dev);
    }
}


static int dvb_net_set_mac (struct net_device *dev, void *p)
{
    struct dvb_net_priv *priv = netdev_priv(dev);
    struct sockaddr *addr=p;

    memcpy(dev->dev_addr, addr->sa_data, dev->addr_len);

    if (netif_running(dev))
        schedule_work(&priv->restart_net_feed_wq);

    return 0;
}


static int dvb_net_open(struct net_device *dev)
{
    struct dvb_net_priv *priv = netdev_priv(dev);

    priv->in_use++;
    dvb_net_feed_start(dev);
    return 0;
}


static int dvb_net_stop(struct net_device *dev)
{
    struct dvb_net_priv *priv = netdev_priv(dev);

    priv->in_use--;
    return dvb_net_feed_stop(dev);
}

static const struct header_ops dvb_header_ops = {
    .create     = eth_header,
    .parse      = eth_header_parse,
    .rebuild    = eth_rebuild_header,
};


static const struct net_device_ops dvb_netdev_ops = {
    .ndo_open       = dvb_net_open,
    .ndo_stop       = dvb_net_stop,
    .ndo_start_xmit     = dvb_net_tx,
    .ndo_set_rx_mode    = dvb_net_set_multicast_list,
    .ndo_set_mac_address    = dvb_net_set_mac,
    .ndo_change_mtu     = eth_change_mtu,
    .ndo_validate_addr  = eth_validate_addr,
};

static void dvb_net_setup(struct net_device *dev)
{
    ether_setup(dev);

    dev->header_ops     = &dvb_header_ops;
    dev->netdev_ops     = &dvb_netdev_ops;
    dev->mtu        = 4096;

    dev->flags |= IFF_NOARP;
}

static int get_if(struct dvb_net *dvbnet)
{
    int i;

    for (i=0; i<DVB_NET_DEVICES_MAX; i++)
        if (!dvbnet->state[i])
            break;

    if (i == DVB_NET_DEVICES_MAX)
        return -1;

    dvbnet->state[i]=1;
    return i;
}

static int dvb_net_add_if(struct dvb_net *dvbnet, u16 pid, u8 feedtype)
{
    struct net_device *net;
    struct dvb_net_priv *priv;
    int result;
    int if_num;

    if (feedtype != DVB_NET_FEEDTYPE_MPE && feedtype != DVB_NET_FEEDTYPE_ULE)
        return -EINVAL;
    if ((if_num = get_if(dvbnet)) < 0)
        return -EINVAL;

    net = alloc_netdev(sizeof(struct dvb_net_priv), "dvb", dvb_net_setup);
    if (!net)
        return -ENOMEM;

    if (dvbnet->dvbdev->id)
        snprintf(net->name, IFNAMSIZ, "dvb%d%u%d",
             dvbnet->dvbdev->adapter->num, dvbnet->dvbdev->id, if_num);
    else
        /* compatibility fix to keep dvb0_0 format */
        snprintf(net->name, IFNAMSIZ, "dvb%d_%d",
             dvbnet->dvbdev->adapter->num, if_num);

    net->addr_len = 6;
    memcpy(net->dev_addr, dvbnet->dvbdev->adapter->proposed_mac, 6);

    dvbnet->device[if_num] = net;

    priv = netdev_priv(net);
    priv->net = net;
    priv->demux = dvbnet->demux;
    priv->pid = pid;
    priv->rx_mode = RX_MODE_UNI;
    priv->need_pusi = 1;
    priv->tscc = 0;
    priv->feedtype = feedtype;
    reset_ule(priv);

    INIT_WORK(&priv->set_multicast_list_wq, wq_set_multicast_list);
    INIT_WORK(&priv->restart_net_feed_wq, wq_restart_net_feed);
    mutex_init(&priv->mutex);

    net->base_addr = pid;

    if ((result = register_netdev(net)) < 0) {
        dvbnet->device[if_num] = NULL;
        free_netdev(net);
        return result;
    }
    printk("dvb_net: created network interface %s\n", net->name);

    return if_num;
}

static int dvb_net_remove_if(struct dvb_net *dvbnet, unsigned long num)
{
    struct net_device *net = dvbnet->device[num];
    struct dvb_net_priv *priv;

    if (!dvbnet->state[num])
        return -EINVAL;
    priv = netdev_priv(net);
    if (priv->in_use)
        return -EBUSY;

    dvb_net_stop(net);
    flush_work(&priv->set_multicast_list_wq);
    flush_work(&priv->restart_net_feed_wq);
    printk("dvb_net: removed network interface %s\n", net->name);
    unregister_netdev(net);
    dvbnet->state[num]=0;
    dvbnet->device[num] = NULL;
    free_netdev(net);

    return 0;
}

static int dvb_net_do_ioctl(struct file *file,
          unsigned int cmd, void *parg)
{
    struct dvb_device *dvbdev = file->private_data;
    struct dvb_net *dvbnet = dvbdev->priv;

    if (((file->f_flags&O_ACCMODE)==O_RDONLY))
        return -EPERM;

    switch (cmd) {
    case NET_ADD_IF:
    {
        struct dvb_net_if *dvbnetif = parg;
        int result;

        if (!capable(CAP_SYS_ADMIN))
            return -EPERM;

        if (!try_module_get(dvbdev->adapter->module))
            return -EPERM;

        result=dvb_net_add_if(dvbnet, dvbnetif->pid, dvbnetif->feedtype);
        if (result<0) {
            module_put(dvbdev->adapter->module);
            return result;
        }
        dvbnetif->if_num=result;
        break;
    }
    case NET_GET_IF:
    {
        struct net_device *netdev;
        struct dvb_net_priv *priv_data;
        struct dvb_net_if *dvbnetif = parg;

        if (dvbnetif->if_num >= DVB_NET_DEVICES_MAX ||
            !dvbnet->state[dvbnetif->if_num])
            return -EINVAL;

        netdev = dvbnet->device[dvbnetif->if_num];

        priv_data = netdev_priv(netdev);
        dvbnetif->pid=priv_data->pid;
        dvbnetif->feedtype=priv_data->feedtype;
        break;
    }
    case NET_REMOVE_IF:
    {
        int ret;

        if (!capable(CAP_SYS_ADMIN))
            return -EPERM;
        if ((unsigned long) parg >= DVB_NET_DEVICES_MAX)
            return -EINVAL;
        ret = dvb_net_remove_if(dvbnet, (unsigned long) parg);
        if (!ret)
            module_put(dvbdev->adapter->module);
        return ret;
    }

    /* binary compatibility cruft */
    case __NET_ADD_IF_OLD:
    {
        struct __dvb_net_if_old *dvbnetif = parg;
        int result;

        if (!capable(CAP_SYS_ADMIN))
            return -EPERM;

        if (!try_module_get(dvbdev->adapter->module))
            return -EPERM;

        result=dvb_net_add_if(dvbnet, dvbnetif->pid, DVB_NET_FEEDTYPE_MPE);
        if (result<0) {
            module_put(dvbdev->adapter->module);
            return result;
        }
        dvbnetif->if_num=result;
        break;
    }
    case __NET_GET_IF_OLD:
    {
        struct net_device *netdev;
        struct dvb_net_priv *priv_data;
        struct __dvb_net_if_old *dvbnetif = parg;

        if (dvbnetif->if_num >= DVB_NET_DEVICES_MAX ||
            !dvbnet->state[dvbnetif->if_num])
            return -EINVAL;

        netdev = dvbnet->device[dvbnetif->if_num];

        priv_data = netdev_priv(netdev);
        dvbnetif->pid=priv_data->pid;
        break;
    }
    default:
        return -ENOTTY;
    }
    return 0;
}

static long dvb_net_ioctl(struct file *file,
          unsigned int cmd, unsigned long arg)
{
    return dvb_usercopy(file, cmd, arg, dvb_net_do_ioctl);
}

static int dvb_net_close(struct inode *inode, struct file *file)
{
    struct dvb_device *dvbdev = file->private_data;
    struct dvb_net *dvbnet = dvbdev->priv;

    dvb_generic_release(inode, file);

    if(dvbdev->users == 1 && dvbnet->exit == 1) {
        fops_put(file->f_op);
        file->f_op = NULL;
        wake_up(&dvbdev->wait_queue);
    }
    return 0;
}


static const struct file_operations dvb_net_fops = {
    .owner = THIS_MODULE,
    .unlocked_ioctl = dvb_net_ioctl,
    .open = dvb_generic_open,
    .release = dvb_net_close,
    .llseek = noop_llseek,
};

static struct dvb_device dvbdev_net = {
    .priv = NULL,
    .users = 1,
    .writers = 1,
    .fops = &dvb_net_fops,
};


void dvb_net_release (struct dvb_net *dvbnet)
{
    int i;

    dvbnet->exit = 1;
    if (dvbnet->dvbdev->users < 1)
        wait_event(dvbnet->dvbdev->wait_queue,
                dvbnet->dvbdev->users==1);

    dvb_unregister_device(dvbnet->dvbdev);

    for (i=0; i<DVB_NET_DEVICES_MAX; i++) {
        if (!dvbnet->state[i])
            continue;
        dvb_net_remove_if(dvbnet, i);
    }
}
EXPORT_SYMBOL(dvb_net_release);


int dvb_net_init (struct dvb_adapter *adap, struct dvb_net *dvbnet,
          struct dmx_demux *dmx)
{
    int i;

    dvbnet->demux = dmx;

    for (i=0; i<DVB_NET_DEVICES_MAX; i++)
        dvbnet->state[i] = 0;

    return dvb_register_device(adap, &dvbnet->dvbdev, &dvbdev_net,
                 dvbnet, DVB_DEVICE_NET);
}
EXPORT_SYMBOL(dvb_net_init);